Marbles in a can

[toomanymodz]

I just installed a newly rebuilt 2004R in a customer's car and when we took it for a test drive it made a horrible sound. All sounded fine until the customer got into boost at around 60 mph and then it sounded like marbles inside the casing and it was very loud. It sounded as if something was trying to go through the transmission case and join me through the floor! He let off the throttle and the noise continued for a second or two and then stopped.

Any ideas what this is? A loose bolt inside the transmission perhaps? I checked under the car very thoroughly and didn't see any signs of anything a-miss. The driveshaft was tight, nothing around the torque converter etc. Something definitely is loose inside the tranny. It literally scared me to where I wanted to lift my feet off the floor and get as far away from it as possible!

 

[Pronto]

I had a new torque converter once in a non TB that made a noise like that. The trans builder installed a new converter and the sound went a away.

 

[toomanymodz]

I had a new torque converter once in a non TB that made a noise like that. The trans builder installed a new converter and the sound went a away.

The torque converter was the same as before. Only the transmission was refreshed. But still a good theory. I'll send it out for inspection when I pull the tranny.

 

[No disintegrations]

I wonder if it was a ton of knock from the engine? Typically stuff that's blowing up from grenade type debris doesn't even make the noise you'd think. It just dies and that's it. Almost the entire trans internals are free from bolts, it's all snap rings. (Valve body, stator support have bolts) The magnet may tell a tale.

Detonation does however sound like marbles.

 

[TurboBuRick]

What drive shaft loop? Check around the front u joint for signs of contact.

 

[toomanymodz]

What drive shaft loop? Check around the front u joint for signs of contact.

Well, the car has one of those cheap loops that looks more like a square than a loop. It is VERY close to the top of the shaft and I see signs of it touching. I gently jacked up the trans and I could make it touch. Just got done ordering a real driveshaft loop (the one by Metco). I believe this will solve the problem. Thanks for the advice! Gotta love this forum!

 

[Pronto]

Removing the loop for now to test might be worth the time.